Ifi nano iDSD BL - roon and battery life?

How long are folks seeing the battery last on your ifi nano iDSD BL? If you don’t mind.

I’m running an iPhone 6s with the ifi nano iDSD BL and Focal Spirit One S headphones with roon, all on straight battery power (iPhone and ifi). What type of duration should I be seeing out of the ifi? The iphone battery pushing roon lasts forever, the ifi, not so much.

What are you folks seeing?